Writing is demanding. It demands that you are honest with yourself, willing to share experiences with meaning regardless of what other people think. It often pushes a writer beyond the comfort zone and sometimes into exhaustion. You have to work very hard, be a self starter and relentless editor. You have to be a reader and get involved with other people and their books. A degree in writing helps but don't let it stop you if you don't have it. Basically you need talent and a strong work ethic.